Regardless of the outcome of this particular issue, it doesn't address the wider problem, in that your wallet is still closed source. Even if Google didn't have access to the seed as you state (which again, because they are closed source, we will never know), the issue is that they could have. All users of Coinomi have to have complete trust in both your programming skills and your honesty.

The oft repeated mantra of "Don't trust. Verify." is apt here. With closed source software, it is impossible to verify, and you are forced to trust.